He was sentenced to three years in prison in 1998, after pleading guilty to 21 sample charges.

Ms O'Keeffe subsequently took legal action against the Department of Education, arguing that the State had failed to put in place appropriate protection measures to prevent and stop systematic sexual abuse at her school.

However, the High Court dismissed her claim that the State was liable.

The Supreme Court subsequently upheld that ruling, finding that while the State funded the education system, the management role of the Catholic Church was such that the State could not be held vicariously liable for the criminal acts of the teacher.

The European Court of Human Rights was Ms O'Keeffe's final legal opportunity to have the State held liable for the sexual abuse she suffered.

The ruling could have significant implications for other victims of abuse in Irish schools.

Call for legislation to protect children

Ms O'Keeffe said what drove her on for the last number of years was knowing that the Supreme Court was wrong and that no child should be abused in school.

Speaking after the ruling, Ms O'Keeffe said guidelines are insufficient and it is now up to the State to put legislation in place to protect children.

She said the effect of abuse on her life will never go away, but this case has shown that there must be protection put in place for children.

Ms O’Keeffe said the whole point of the case she brought was that a complaint of abuse was made in 1971 and that had it been acted upon she would not have been abused in 1973.

"Abusers hide behind guidelines. Legislation is what will secure the protection of the children, so it is up to the State now to put the legislation in place," she said.

She said the judgment was an important one for the school children in Ireland.

"It's the children in the schools that this case was fought for. It was fought for the protection of boys and girls at a very young age who simply should be protected," she said.

Ms O’Keeffe said she hoped now that the 135 people the State claims agency wrote to following judgments made against her in the High and Supreme Courts would receive apologies.

Her solicitor Ernest Cantillon said the State had 135 cases pending this judgment and they should be dealt with by the State as soon as possible.

Mr Cantillon said a wrong had been done to Ms O'Keeffe.

He also said Ms O’Keeffe should not have to ask for an apology from the State. She should be given one, he said.

Minister for Education Ruairi Quinn this afternoon said that while his sympathy is very much with Ms O'Keeffe, he will have to consider the judgment and receive advice before he can give a reaction.

Asked if he would give Ms O'Keeffe an apology, he said that he is glad she has got a result, but he will have to consider the implications of the ruling.

More than 80 cases dropped after agency letter

More than 80 people are believed to have dropped their legal actions against the State over alleged abuse in day schools since receiving letters stating they were at risk of having to pay its legal costs.

However, there are currently 45 cases before the courts.

A spokesperson for the State Claims Agency told RTÉ News that it wrote to 135 people who were taking cases similar to Ms O'Keeffe's in the first three months of 2009.

This followed the Supreme Court's rejection of Ms O'Keeffe's claim for damages.

The letter stated that the court had found that the Minister for Education had no liability in the O'Keeffe case.

The spokesperson said the letter "invited them to withdraw their actions and volunteered that the State would not seek its legal costs" from those who did so.

The spokesperson said that in April 2009, the agency wrote again to those who had not discontinued their civil actions.

It offered them the opportunity to drop their cases within 21 days, warning that after that period it would move a motion in the courts to have their cases struck out.

The agency said it would also seek a ruling that they pay the State's legal costs.

The spokesperson said "a handful" of the 135 people had had their cases dealt with by the courts since then, including some who won damages.

He said that "in a larger number of cases, the plaintiffs had voluntarily discontinued proceedings".